Hygroscopic ingredients in chewing gum cause the chewing gum to pick up and absorb moisture during and after manufacture. Excessive moisture pick-up, occurring in chewing gum containing significant quantities of hygroscopic ingredients, can soften these gums causing wrapping difficulties and slower processing of the gums. Moisture pick-up, and the resulting softening, can also cause the gum to spread during sheeting, making it difficult to maintain proper length and width of the chewing gum sheets.
The hygroscopic chewing gum ingredients which can cause these processing difficulties after absorbing moisture, include particularly sodium chloride, ammonium chloride, potassium chloride, calcium chloride, and other chloride salts, salt substitutes and mixtures thereof. Other hygroscopic ingredients can cause these processing difficulties to a lesser extent, including licorice powder, powdered fruit, spray dried fruit flavors, cocoa powder, powdered onion and garlic, brown sugar, dried honey solids and corn syrup solids. Ordinarily, processing difficulties do not occur in chewing gums which contain very minor quantities of one or more hygroscopic ingredients. The excessive moisture pick-up, and the resulting processing difficulties, are most apparent for chewing gums containing more than 2% by weight hygroscopic ingredients, and particularly for chewing gums containing more than 3% by weight hygroscopic ingredients. Chewing gums containing more than 2% by weight hygroscopic ingredients are referred to herein as "hygroscopic chewing gums."
U.S. Pat. No. 5,139,974, issued to Patel et al., discloses the use of encapsulated salts to enhance flavor and sweetness of chewing gum. The salt, which can include a blend of about 1 to 4 parts by weight sodium chloride per part by weight potassium chloride, is coated or encapsulated to provide a delayed release. The salt, which constitutes about 0.01-0.5 weight percent of the gum, can be pre-mixed with molten chewing gum base to eliminate a "moist spot" problem caused by hygroscopicity of the salt. The base is then cooled and solidified before being added to the chewing gum formula.
U.S. Pat. No. 4,889,727, issued to Dave et al., discloses using a minor quantity of cocoa powder to enhance the flavor of a synthetic chewing gum base. The amount of cocoa powder is limited to levels which do not impart a noticeable chocolate flavor to the chewing gum and cannot, in any event, exceed about 2.4 percent of the gum base.
U.S. Pat. No. 4,208,431, issued to Friello et al., and U.S. Pat. No. 4,217,368, issued to Witzel et al., both disclose the addition of particulated sweeteners to a chewing gum base, in order to achieve delayed release. Included among the mentioned sweeteners are the ammonium, sodium and potassium salts of glycyrrhizin.